Impeachment. Impeachment in the United States is an enumerated power of the legislature that allows formal charges to be brought against a civil officer of government for crimes alleged to have been committed. Most impeachments have concerned alleged crimes committed while in office, though there have been a few cases in which Congress has impeached and convicted officials partly for prior crimes.The actual trial on such charges, and subsequent removal of an official upon conviction, is separate from the act of impeachment itself. Impeachment proceedings have been initiated against several presidents of the United States. Andrew Johnson and Bill Clinton are the only two presidents to have been successfully impeached by the House of Representatives, and both were later acquitted by the Senate. The impeachment process against Richard Nixon was technically unsuccessful, as Nixon resigned his office before the vote of the full House for impeachment, but successful in the broader sense of leading to Nixons departure. To date, no U.S. President has been removed from office by impeachment and conviction. Impeachment is analogous to indictment in regular court proceedings; trial by the other house is analogous to the trial before judge and jury in regular courts. Typically, the lower house of the legislature impeaches the official and the upper house conducts the trial. Impeachment proceedings may be commenced by a member of the House of Representatives on her or his own initiative, either by presenting a list of the charges under oath, or by asking for referral to the appropriate committee. The impeachment process may be initiated by nonmembers. For example, when the Judicial Conference of the United States suggests a federal judge be impeached, a charge of actions constituting grounds for impeachment may come from a special prosecutor, the President, or state or territorial legislature, grand jury, or by petition. The type of impeachment resolution determines the committee to which it is referred. A resolution impeaching a particular individual is typically referred to the House Committee on the Judiciary. A resolution to authorize an investigation regarding impeachable conduct is referred to the House Committee on Rules, and then to the Judiciary Committee. The House Committee on the Judiciary, by majority vote, will determine whether grounds for impeachment exist. If the Committee finds grounds for impeachment they will set forth specific allegations of misconduct in one or more articles of impeachment. The Impeachment Resolution, or Article(s) of Impeachment, are then reported to the full House with the committees recommendations. The House debates the resolution and may at the conclusion consider the resolution as a whole or vote on each article of impeachment individually. A simple majority of those present and voting is required for each article or the resolution as a whole to pass. If the House votes to impeach, managers (typically referred to as House managers, with a lead House manager) are selected to present the case to the Senate. Recently, managers have been selected by resolution, while historically the House would occasionally elect the managers or pass a resolution allowing the appointment of managers at the discretion of the Speaker of the United States House of Representatives. These managers are roughly the equivalent of the prosecutiondistrict attorney in a standard criminal trial.